Objective:To study the expression levels of long non-coding RNA(lncRNA)H19 and insulin-like growth factor 2(IGF2)genes in breast cancer tissue,and to analyze their imprinting status.Methods:Real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of H19 and IGF2 mRNA in breast cancer tissue and adjacent tissue,and the differences in the expressions of H19 and IGF2 mRNA in breast cancer tissue and adjacent tissue were analyzed;single nucleotide polymorphism(SNP)was used to distinguish the allele expression status(homozygous or heterozygous).For heterozygous IGF2(Apa Ⅰ site)or H19(Alu Ⅰ site)in genomic DNA,imprinting analysis was used to detect the imprinting status of H19 and IGF2 in breast cancer tissue,that were maintenance of imprinting(MOI)or loss of imprinting(LOI);the relationship between the expressions of H19 and IGF2 and molecular subtypes in breast cancer tissue were also analyzed.Results:The RT-qPCR results showed that the expression levels of H19 and IGF2 mRNA in breast cancer tissue were higher than those in adjacent tissue(P<0.01).There was a positive correlation between the expression levels of H19 mRNA and IGF2 mRNA(r=0.567,P<0.01).Compared with adjacent tissue,the expression levels of H19 mRNA in cancer tissue of the breast cancer patients with various molecular subtypes were increased(P<0.05 or P<0.01).LOI was observed in both H19 and IGF2 in breast cancer tissue,and the incidence of IGF2 LOI was 36.7%,which was higher than that of H19 LOI(4.3%).The RT-qPCR results showed that the expression level of IGF2 mRNA in breast cancer tissue in IGF2 LOI group was significantly higher than that in IGF2 MOI group(P<0.01).Conclusion:The expression levels of H19 and IGF2 mRNA in breast cancer tissue are significantly higher than those in adjacent tissue.The incidence of IGF2 LOI is higher than that of H19 LOI,and IGF2 LOI may be one of the key factors in the pathogenesis of breast cancer.
关键词
乳腺肿瘤/长链非编码RNA/H19/胰岛素样生长因子2/印记丢失/单核苷酸多态性
Key words
Breast neoplasm/Long chain non-coding RNA H19/Insulin-like growth factor 2/Loss of imprinting/Single nucleotide polymorphism